Rheostat.



L. G. EILBRTSEN.

` RHEosTAT. APPLI'OATION FILED HAR. 28, 1911'. 1,01 9,6 1 6. Patented Mar. 5, 1912.

-2 SHEETS-SHEET 1.

- J @www L. C. EILERTSEN.

RHEOSTAT.

APPLIOATION FILED 111111.29, 1911.

1,01 9,61 6. A Patented M9115, 1912.

2 SHEETS-MEET 2.

LUCIEN. CHARLES EILERTSEN, or PARIS, FRANCE.

RHEOSTAT.

ASpecification of Letters Patent.

Application led March 28, 1911. Serial No. 617,468.

To ail whom'it may concern:

Be it known that I, LUGIEN CHARLES EILERTSEN, a citizen of the French Republic, and resident o f Paris, France, have in vented a certain new and useful Rheostat, of which the following is a specification.

This invention relates to a new rheostat adapted to be controlled from a distance.

In the accompanyingdrawing's, iven by way of example: Figure 1 shows iagrammatically one form of embodiment of a rheostat constructed according tol 'the principles of the present invention; Fig. 2 shows in a similar manner a modified form based on the same principle.' Fig. 3 shows a verti cal section of an actuating device.

In the form of embodiment shown by Fig. l, the rheostat comprises two vessels A and B having preferably a tubular shape oo mmunicating through tube 3 and filled with mercury up to a determined level L. Ar-

'ranged around the vessel A and passing through the wall of this vessel is a series lof conducting4 wiresA C which are insulated from each other and the inner ends D of which are freefinside the vessel A while the other ends D are soldered at intervals to a long wire R which is wound in the shapeof a helix or arranged in any other 'manner so as to form a resistance through which the current to be controlled passes. The receptacle B is provided with a tubular extension T and is closed at its upper part. A tube F communicating with a receptacle G descends into the vessel B, the receptacle G containing mercury so as to maintain the level of fluid in a constant manner at h and to compensate the loss of mercury which might occur by evaporationor owing to any other cause. The tube A may receive abovethe mercury a layer of a non-conducting liquid H intended to protect the mercury and the ends of the conducting wires from any alteration.

The tubular extension T communicates with a small apparatus which is intended to produce the variations of pressure which cause the variations of themercury level. This apparatus may be stationary or be held inthe hand and be'constructed in Ithe followin manner: Arran ed at the u per end of a older X is a tu e c providhd with a cock L-and communicating at one end by means of a flexible tube N with any suitable source of com ressed air and at the other end'with two exible tubes o and o the first `both vessels A and one connects it with the tubular extension T and the other'with asmall apparatuswhich serves to indicate .the level ofthe mercury in the rheostat and consequently the` intensity of the current. A third' rigid tube O provided with a cock L serves to regulate the escape. The -controlling apparatus showing the level of the mercury in the rheostat is also formed of two tubes, 1 and 2 communicating with each other and filled with mercury up to a determined level; the said two tubes are engaged 'into each other so that the inner tube 1 plays the part of a bell in which the mercury descends while t rises in the outer tube 2. The bell l communicat'es with the tube 7c through the medlum of the tube O and' is subjected to the same `fvariations of pressure as the rheostat proper.

This apparatus may be suspended from the celling and be raised and lowered by means of a pulley; it may also be rendered movable by any other.means but in sucha manner that it is always positioned in front of the eyes of the operator.

The working of the device will be readily PatentedMar; 5, 1912.

understood from the foregoing specification. -Y

The level of the mercury being the same in l the current passes through the entire resistance R; if it is de? sired to put the latterout of the circuit all that will be necessary is to increase the air pressure by opening the cock L, the more this pressure increases the higher the level of the mercury rises in the vessel A and correspondingly descends in the vessel B; in proportion to the increase of the pressure the mercury will come into contact with a larger number of conductors Z thus can-4 celing a corresponding proportion of the resistance R. For reducing the pressure the cock L is opened; the mercurylevel therefore will descend so that the resistance is increased; asv readily seen this resistance is controlled by simply varying the pressure and consequently the level. The same fluctuations of the level will be reproduced on the indicating apparatus thereby allowing of the working of the rheostat to beacourately controlled. The current may also be caused to flow between the end E of the resistance and a conductor V dipping at all times direct into the mercury, the results' obtained will be the same. In practice, as it is useful to be able to perform by means of a single finger the two maneuvers necessary 'for the workin arran ement shown y Fig. 3 may'be adapt ed. ere the two cocks L and.L are replaced by two valves S and S which alter- 5 nately open and'close two ports P and P. The port P establishes the communication between the chamber w and jthe chamber m while port P establishes the communication between the chamber w and the atmosphere. The ychamber m receives compressed air from the tubular extension T is closed by a iston and a third valve S which is held 1n a closed position by a spring in such a manner that by pushing on a button U by means of a handle' Y the said piston is caused to descend and bears through the medium of a rod on the va ve S which is also held in a closed position by al spring. The valve S descends and the compressed air passes from the compartment intothe compartment w and from here into the eneral duct through the tubular extension thus increasing the pressure and thereby the height of the mercury level in A and consequently the intensity of the current. When the pressure is no longer exerted on the handle-the valvesl S and S^are closed by their springs and the pressure and coni sequently the height of the mercury column as well as the intensity ofthe current remain the same.v i

If it is desired to reduce the pressure and' consequently the intensity of the current the inverse motion is performed; the handle is raised by means of the same linger whereby the rod H is raised the horizontally bent part H of which bears on a rod I so as to raise the valve S. The compressed air escape from the chamber X through the 40 passage P, the pressure is reduced in the duct and consequently the intensity ofthe Fig. 2 shows a modiied form of the'apparatus based on the same principle, the resistance R being wound around a bell B and dipping with itinto the mercury. The variations of the height of the level of mercury in the receptacle A are obtained by the variation of the pressure produced in the bell B..y The current iows between a conductor V which is in contact with the mercury, and the end F of the resistance. As to the working of this modified form it is exactly the same as that of the apparatus 55 shown by Fig. 1. It is needless to say that many combinations based on the sameprin- -ciple may be devised.. Various means may also be employed for varying the level of the mercury; the pressure of water may for instance be employed or any other similar means, the result would be the same. It would equally be possible to employ another conducting liquid in the place of the mercury. 4

The rheostat described above, owing to 'of the apparatus, the

1. In a rheostat of the 'combination of two communicating vessels,

. conducting liquid, a

its great sensitiveness andthe' possibility of' A being controlled from a distance is 4very suitable for graduating the tcm eraturein hot air apparatusesI Where the air is 'heated means of a resistance which is more or less Aheated by the passage of a current.

Having now fully described my -said ini A,

vention, what I claim and desire to secure by Letters Patent, is: v

kind described the a conductin liquid in said vessels, -a resistance coil a apted to 'coperate with said ressure fluid adapted to exert pressure on t e liquid contained in one of said vessels and an indicator receiving the same pressure as the said liquid and ada ted to show this pressure, substan tial y as and for the urposeset forth.

2. A rheostat inclu ing spaced intercommunicating vessels, a conductingliquid in each, circuit terminals in one vessel, one of said terminals being at all times in contact y with the liquid therein, the other terminal including resistance to be varied as the depth of liquid varies, pressure means for directly varying the depth of`the liquid in said other vessel to reversely vary the depth in the first named vessel, and means remote from said vessels for controlling the pressure means. A

3. A rheostat including spaced intercommunicating vessels, a conducting liquidl in each, circuit terminals in one vessel, one of said terminals being at all times in contact with the liquid therein, the other terminal includin resistance to be varied as the depth of li uid varies, pressure means for directly varying the depth of the liquid in said other vessels to reversely vary the depth in the rst named vessel, meansremote from said vessels for controlling the pressure means, and an indicator to `indicate the depth of liquid in the irstnamed vessel.

4. A rheostat including spaced intercommunicating vessels, a conducting liquid in each, circuit terminals in one Vessel, one ofy said terminals being at all times in contact with the liquid therein, the other terminal includin resistance to be varied as the depth o liquid varies, pressure means for ioo los

directly varying the depth of the liquid in said other vessel to reversely vary the depth in the first named vessel, means remote from said vessels for controlling the pressure means, and an indicator open to the pressure means and adapted to indicate the depth of the liquid in the first named vessel.

5. A rheostatincluding spaced ,intercommunicating vessels, a conducting'liquid in each, circuit terminals in one vessel, one of said terminals being at all `times in contact with the liquid therein, the other terminal including resistance to be varied as the depth of liquid varies, pressure means for directly Varying the depth of the liquid in said other vessel to reversely vary the depth in the first named vessel, means remote from said vessels for contolling the pressure means, and an indicatoJ to show the depth of liquid in the first named vessel, said indicator comprising an open vessel containing liquid, and an interior bell operable in said open vessel and itselfl open to the pressure means. 10

In testimony whereof I have hereunto set 4 ymy hand in presence of two Witnesses. 

